By Stephanie Stahl

PHILADELPHIA (CBS) — On Friday, the Centers for Disease Control and Prevention changed course again and dropped controversial testing advice that caused a big backlash. This comes as cases are on the rise in Pennsylvania and New Jersey.

Friday was the fourth straight day New Jersey has seen more than 400 new coronavirus cases. In fact the for the past two days, daily case counts exceeded 500 in the Garden State.

Once again, young people acting irresponsibly are getting much of the blame.

“You got back-to-back days where we have clocked some big numbers,” Gov. Phil Murphy said.

Murphy is urging caution again. After significant declines in coronavirus cases, New Jersey is seeing an uptick.

“Some linked to gatherings, some linked to celebratory gatherings, like parties, and some solemn gatherings as in funerals. No matter the reason, this increase in cases, reminds us this virus is unrelenting. It treats everyone the same. We are fighting an invisible enemy,” Department of Health Commissioner Judith Persichilli said.

New Jersey health officials say that the increased cases are coming mainly from Ocean and Monmouth Counties and are linked to young people.

“About 27% of these new cases were among 20 to 29-year-old residents and about 17% were among 10 to 19-year-olds,” Persichilli said.

It’s gathering like this — people who the governor calls knuckleheads — partying without masks or social distancing.

“We cannot let our guard down, we must keep up all public health measures that have allowed us to flatten the curve of COVID-19,” Persichilli said.

In Pennsylvania, there is a similar slight increase in cases among young people.

In another reversal from the CDC, anyone who’s been in close contact with someone infected with COVID-19 is being advised to get tested.

The agency is dropping a controversial piece of guidance and is returning to its previous recommendation, getting rid of language posted last month that said people didn’t need to get tested if they didn’t feel sick.

The CDC now says anyone who has been within six feet of an infected person for at least 15 minutes should get a test.

In a statement, the agency called the changes a “clarification” that was needed “due to the significance of asymptomatic and pre-symptomatic transmission.”

Stephanie Stahl